pandas.core.groupby.DataFrameGroupBy.idxmax

DataFrameGroupBy.idxmax(axis=0, skipna=True)

Return index of first occurrence of maximum over requested axis. NA/null values are excluded.

Parameters:

axis : {0 or ‘index’, 1 or ‘columns’}, default 0

0 or ‘index’ for row-wise, 1 or ‘columns’ for column-wise

skipna : boolean, default True

Exclude NA/null values. If an entire row/column is NA, the result will be first index.

Returns:

idxmax : Series